Anti-capitalism protesters were continuing to demonstrate near the London Stock Exchange as part of the worldwide movement spawned by Occupy Wall Street.

Up to 100 tents were pitched at a makeshift camp at the foot of the steps of St Paul's Cathedral, though of the thousands of protesters who descended on the area on Saturday, only around 400 remained on Sunday morning.

Attempts to occupy the Stock Exchange in nearby Paternoster Square have been thwarted by police barricades.

As the Sunday morning bells pealed, awaking a good many campers from their slumbers, those attending services at St Paul's seemed happy to pick their way through the sleeping bags and tents in their path.

The atmosphere appeared relaxed and police made no attempt to move the protesters on, though they instructed them not to block the cathedral steps.

Scotland Yard has said it would be "illegal and disrespectful" to camp in front of the cathedral, but a spokesman said they were not moving anyone on "at this time".

Ben Doran, 21, a music student, said a clergyman had come out onto the cathedral steps to express his support for the protesters. "He said there was no issue and that people were treating the site respectfully and he was happy for it to carry on."

Some of those who slept out on Saturday night were intending to leave today – back to homes, jobs or college courses – but said they planned to return next weekend.

The Occupy Wall Street movement seems to have attracted many first-time protesters, including Ollie Taylor, 23, from Aldershot. "This is the first protest I've ever been to, but I feel really, really strongly about this issue," he said. "I really think this is going to snowball."

Taylor said he would return to his full-time job as a photography studio assistant on Monday. "I have to work to pay off my student debt. It was £20,000. Now it's about £4,000, and I've been working to the bone to pay it off," he said. "But I will be back next weekend."

Sean, 33, an electrical engineering graduate, said: "I have never been involved in this sort of action before. This is civil disobedience. It's not a protest."

Police appeared relaxed. They kept a visible but low presence, and many officers chatted and mingled with the protesters.

"It's really, really relaxed. You can't emphasis how great the police are being. Some of them seem to be showing genuine interest," said Taylor.

A spokesman for the protesters said the demonstration was to "challenge the bankers and the financial institutions which recklessly gambled with the economy. This occupation and 20 other occupations all around the UK have been directly inspired by what's happening all across America and especially Wall Street," he said.

A field kitchen providing basics donated by wellwishers had been set up at the side of the cathedral. A media support centre, powered by a generator, streamed activities at the camp live on to the internet.

Some worshippers at the cathedral expressed their support. "The general atmosphere within the church this morning has been quite supportive," said Diane Richards, 36, a mental health support worker. "The protesters have kept it well organised, they are trying to keep a very peaceful demonstration."

Five arrests were made on Saturday, three for assault on police and two for public order offences.